39 research outputs found
Generalized Conformal Quantum Mechanics of D0-brane
We study the generalized conformal quantum mechanics of the probe D0-brane in
the near horizon background of the bound state of source D0-branes. We
elaborate on the relationship of such model to the M theory in the light cone
frame.Comment: 14 pages, RevTeX, revised version with added references to appear in
Phys. Rev.
Effective Actions for Massive Kaluza-Klein States on AdS_3 x S^3 x S^3
We construct the effective supergravity actions for the lowest massive
Kaluza-Klein states on the supersymmetric background AdS_3 x S^3 x S^3. In
particular, we describe the coupling of the supergravity multiplet to the
lowest massive spin-3/2 multiplet which contains 256 physical degrees of
freedom and includes the moduli of the theory. The effective theory is realized
as the broken phase of a particular gauging of the maximal three-dimensional
supergravity with gauge group SO(4) x SO(4). Its ground state breaks half of
the supersymmetries leading to 8 massive gravitinos acquiring mass in a super
Higgs effect. The holographic boundary theory realizes the large N=(4,4)
superconformal symmetry.Comment: 31 pages, v2: minor change
The Gaugings of Maximal D=6 Supergravity
We construct the most general gaugings of the maximal D=6 supergravity. The
theory is (2,2) supersymmetric, and possesses an on-shell SO(5,5) duality
symmetry which plays a key role in determining its couplings. The field content
includes 16 vector fields that carry a chiral spinor representation of the
duality group. We utilize the embedding tensor method which determines the
appropriate combinations of these vectors that participate in gauging of a
suitable subgroup of SO(5,5). The construction also introduces the magnetic
duals of the 5 two-form potentials and 16 vector fields.Comment: 34 pages, latex, reference added, typo's corrected and minor
improvements mad
Supersymmteric Null-like Holographic Cosmologies
We construct a new class of 1/4-BPS time dependent domain-wall solutions with
null-like metric and dilaton in type II supergravities, which admit a null-like
big bang singularity. Based on the domain-wall/QFT correspondence, these
solutions are dual to 1/4-supersymmetric quantum field theories living on a
boundary cosmological background with time dependent coupling constant and UV
cutoff. In particular we evaluate the holographic function for the
2-dimensional dual field theory living on the corresponding null-like
cosmology. We find that this function runs in accordance with the
-theorem as the boundary universe evolves, this means that the number of
degrees of freedom is divergent at big bang and suggests the possible
resolution of big bang singularity.Comment: 26 pages;v2 references adde
Holography and Defect Conformal Field Theories
We develop both the gravity and field theory sides of the Karch-Randall
conjecture that the near-horizon description of a certain D5-D3 brane
configuration in string theory, realized as AdS_5 x S^5 bisected by an AdS_4 x
S^2 "brane", is dual to N=4 Super Yang-Mills theory in R^4 coupled to an R^3
defect. We propose a complete Lagrangian for the field theory dual, a novel
"defect superconformal field theory" wherein a subset of the fields of N=4 SYM
interacts with a d=3 SU(N) fundamental hypermultiplet on the defect preserving
conformal invariance and 8 supercharges. The Kaluza-Klein reduction of wrapped
D5 modes on AdS_4 x S^2 leads to towers of short representations of OSp(4|4),
and we construct the map to a set of dual gauge-invariant defect operators O_3
possessing integer conformal dimensions. Gravity calculations of and
are given. Spacetime and N-dependence matches expectations from dCFT,
while the behavior as functions of lambda = g^2 N at strong and weak coupling
is generically different. We comment on a class of correlators for which a
non-renormalization theorem may still exist. Partial evidence for the
conformality of the quantum theory is given, including a complete argument for
the special case of a U(1) gauge group. Some weak coupling arguments which
illuminate the duality are presented.Comment: 47 pages, LaTeX, 2 figures, feynmf. v2: fixed minor errors, added
references. v3: fixed more typo
String Theory on Dp-plane waves
We study the spectrum of solvable string models on plane waves descending
from non-conformal Dp-brane geometries. We mainly focus on S-dual F1/D1-waves
in type IIB and type I/heterotic 10D superstrings. We derive the Kaluza-Klein
spectrum of N=1,2 10D supergravities on D1/F1-waves. We compute helicity
supertraces counting multiplicities and R-charges of string excitations in the
plane wave geometry. The results are compared against the expectations coming
from gauge/supergravity descriptions. In the type I case, the Klein, Annulus
and Moebius one-loop amplitudes are computed for ten-dimensional D1-waves. We
test the consistency of the open string descendant by showing that after
modular transformations to the closed string channel, the three amplitudes
combine themselves to reconstruct a complete square (|B>+|C>)^2. Tadpole
conditions are also discussed.Comment: 22 pages, Minor corrections, References adde
Let's Twist Again: General Metrics of G(2) Holonomy from Gauged Supergravity
We construct all complete metrics of cohomogeneity one G(2) holonomy with S^3
x S^3 principal orbits from gauged supergravity. Our approach rests on a
generalization of the twisting procedure used in this framework. It corresponds
to a non-trivial embedding of the special Lagrangian three-cycle wrapped by the
D6-branes in the lower dimensional supergravity. There are constraints that
neatly reduce the general ansatz to a six functions one. Within this approach,
the Hitchin system and the flop transformation are nicely realized in eight
dimensional gauged supergravity.Comment: 31 pages, latex; v2: minor changes, references adde
S-branes and (Anti-)Bubbles in (A)dS Space
We describe the construction of new locally asymptotically (A)dS geometries
with relevance for the AdS/CFT and dS/CFT correspondences. Our approach is to
obtain new solutions by analytically continuing black hole solutions. A basic
consideration of the method of continuation indicates that these solutions come
in three classes: S-branes, bubbles and anti-bubbles. A generalization to
spinning or twisted solutions can yield spacetimes with complicated horizon
structures. Interestingly enough, several of these spacetimes are nonsingular.Comment: 35 pages, 12 figures. V2: JHEP style, expanded reference